Provide some GUI for changing keyboard layout

[lucasmrod]

I'm using a Lenovo Thinkpad with latin-american keyboard layout.

For some reason I got stuck with kb_layout = us and using vim or any other editor to edit config files was super hard when I couldn't even enter the : key (to save/exit vim) because of the mis-configured layout :)

An easy way to change keyboard layout via Super + Alt + Space > Keyboard layout or something like that would have been super helpful.